Model 2651A High Power System SourceMeter® Instrument Reference Manual
Section 3: Functions and features
2651A-901-01 Rev. A / March 2011
3-87
Digital I/O bit weighting
Bit weighting for the digital I/O lines is shown in the following table.
Digital bit weight
Line #
Bit
Decimal weighting Hexadecimal weighting
1 B1
1
0x0001
2 B2
2
0x0002
3 B3
4
0x0004
4 B4
8
0x0008
5 B5
16
0x0010
6 B6
32
0x0020
7 B7
64
0x0040
8 B8
128
0x0080
9 B9
256
0x0100
10 B10
512
0x0200
11 B11
1024
0x0400
12 B12
2048
0x0800
13 B13
4096
0x1000
14 B14
8192
0x2000
Remote digital I/O commands
Commands that control and access the digital I/O port are summarized in the following table. See
(on page 5-1) for complete details on these commands. See the following table
for decimal and hexadecimal values used to control and access the digital I/O port and individual
lines. Use these commands to trigger the Model 2651A using external trigger pulses applied to the
digital I/O port, or to provide trigger pulses to external devices.
Use these commands to perform basic steady-state digital I/O operations such as reading and writing
to individual I/O lines or reading and writing to the entire port.
NOTE
The digital I/O lines can be used for both input and output. You must write a 1 to all digital I/O lines
that are to be used as inputs.
Remote digital I/O commands
Command Description
digio.readbit(
bit
)
Read one digital I/O input line
digio.readport()
Read digital I/O port
digio.writebit(
bit, data
)
Write data to one digital I/O output line
digio.writeport(
data
)
Write data to digital I/O port
digio.writeprotect =
mask
Write protect mask to digital I/O port